January Nobeyama radioheliograph visit Microwave Signatures of Fast CMEs Nat Gopalswamy NASA Goddard Space Flight Center Greenbelt MD USA

January Nobeyama radioheliograph visit Plan of study Select all CMEs with speed > 1500 km/s for the period Look for eruptive and flare signatures If eruptive, compare kinematics from NoRH and LASCO Distinguish disk and Limb Signatures Make new images if needed

January Nobeyama radioheliograph visit Motivation Fast and Wide CMEs important for space weather Identifying a microwave signature may be a useful tool to characterize these CMEs

January Nobeyama radioheliograph visit Initial set of fast events (speed V > 1500 km/s) to look for Microwave activity (38 events in Nobeyama Time Window) CME first appearance V(km/s) Preliminary Survey /03/31 06:12: /04/23 05:27: One frame shows eruption 5:46:20 east limb 1998/05/09 03:35: : :26 west limb 1998/06/04 02:04: NW limb NoRH PE at 1:36 (not in catalog), EIT dimming 1: /05/12 23:26: NoRH Data gap? 2000/11/08 23:06: double eruption (GRL), two NORH AFs 2000/11/25 01:31: NE quadrant appearance of an elongated feature before flare 2001/04/03 03:26: something disappears bet 3:05 &3:25 above AR EIT dim3: /04/05 02:06: (narrow) diffuse behind the limb? Flare in the east 2001/04/10 05:30: disk event 2001/04/18 02:30: well studied. 2001/05/30 00:06: PE (not cataloged) 00:00 to 00:20 east limb 2001/06/11 04:54: (narrow 37 deg) 3:50-4:10 nonradial ejection? 2001/08/15 23:54: backside nothing in NoRH obvious 2001/11/25 23:06: onset before NoRH obs start 2002/04/21 01:27: studied 2002/05/22 03:50: interaction event; cataloged; need shifted HR images 2002/05/30 05:06: EIT at 4:48; 4:55 noRH brightening 2002/07/23 00:42: rhessi HR images available? 2002/08/24 01:27: good event HR images needed 2002/09/27 01:54: SW narrow; eruption at 1:30 SW 2002/10/27 23:18: two events? this CME source is backside? EIT /11/10 03:30: ejecta at 3:20 SW 2003/01/22 23:54: (jet) poor images 2003/05/31 02:30: no EIT westward extension 17 GHz at 2:38; changes ~2:20 SW 2003/06/02 00:30: eruption 00:00 to 00:10? 2003/06/15 23:54: change at~23:10 above east limb; elongation of 17 Ghz at 23: /06/17 23:18: flare started before obs. start 2003/10/31 04:42: (narrow) PE 4:40 - 5:00 not cataloged 2003/11/09 06:30: backside east limb 2004/01/07 04:06: PE 4:10-4:40; first brightening at 3: /01/08 05:06: elongated feature disappears near AR after brightening; same AR 2004/04/11 04:30: SW quad 4:00-4:10 ejection 2004/11/10 02:26: NW quad EW arcade 2005/01/15 06:30: NNW quad bright arcade 2005/01/15 23:06: bad images 2005/07/27 04:54: : PE not cataloged 2005/07/30 06:50: PE not cataloged?

January Nobeyama radioheliograph visit Related issues

January Nobeyama radioheliograph visit Extend the PE-CME Relationship to 2005

January Nobeyama radioheliograph visit Low Frequency Type II Bursts, CMEs, and Space Weather Nat Gopalswamy NASA Goddard Space Flight Center Greenbelt MD USA Observing metric type II bursts alone is not enough to track CMEs into the Heliosphere

January Nobeyama radioheliograph visit Why Study Low-frequency Type II Bursts? Among solar radio bursts, type II bursts are important for space weather because they help remote-sense large- scale mass motion Type II bursts at decameter-hectometric (DH) and longer wavelengths are indicative of fast and wide CMEs that are geoeffective & SEPeffective SEP events due to CME-driven shocks & geomagnetic storms happen when CMEs impinge on Earth’s magnetosphere Type II bursts are also indicative of large-scale interplanetary disturbances that may impact other locations in the heliosphere (e.g. at and enroute to Mars)

January Nobeyama radioheliograph visit Sources of Geoeffective & SEPeffective CMEs 15W N S WE O Dst < nT O - 300nT < Dst < nT O Dst < nT 37/55 = 67% 18/55 = 33% SEP Type II bursts can detect both of these populations

January Nobeyama radioheliograph visit Interplanetary (1973: Malitson et al.) Coronal (1947) Nelson & Labrum, (1985) Gap filled by Wind/WAVES At Decameter-Hectometric (DH) Wavelengths (Bougeret et al. 1995) Ionospheric Cutoff Rs 214 Type II, Type III bursts Type III storms are observed in the IP medium Some type IV less complex SOHO/LASCO FOV 2-32 Rs

January Nobeyama radioheliograph visit 2005/09/10 22:37 UT CME 1893 km/s PA120 Very intense type II radio bursts: Shock-driving capability of CMEs MHz crucial because the associated CMEs just leave the Sun Sky-plane height of the CME is ~9 Ro 8.56 Ro 800 kHz “The bow shocks of fast, large CMEs are strong interplanetary (IP) shocks, and the associated radio emissions often consist of single broad bands starting below ~4 MHz; such emissions were previously called IP type II events.” Cane & Erickson 2005

January Nobeyama radioheliograph visit IP type II bursts “The bow shocks of fast, large CMEs are strong interplanetary (IP) shocks, and the associated radio emissions often consist of single broad bands starting below ~4 MHz; such emissions were previously called IP type II events.” “… metric type II bursts, unlike IP type II events, are not caused by shocks driven in front of CMEs.” Cane & Erickson 2005

January Nobeyama radioheliograph visit A DH Type II & its CME f =0.85MHz  fp = MHz  n = 2.2x10 3 cm -3 when the CME is at 30 Rs Vcme ~ 770 km/s Radio emission tracks CME beyond LASCO FOV 2.86 Rs 3.98 Rs15.58 Rs22.21Rs No Type II yet CME at edge of C3 FOV (30 Rs) at the edge of C2 FOV Type II starts

January Nobeyama radioheliograph visit Type II in various Wavelength Ranges m DH km km type II Metric Type II DH Type II m-km Type II (m not shown) DH Type II (no m) Observed type II features: m – pure metric (ground); DH-decameter-hectometric; km – kilometric; some start at m and go all the way to km (m-to-km) f t

January Nobeyama radioheliograph visit Type II Bursts Organized by CMEs m DH km Speeds, widths & deceleration of CMEs progressively increase for metric, DH, full- range (m-to-km) Type II Bursts, compared to the general population Purely km type IIs due to accelerating CMEs, which form shocks far away from the Sun

January Nobeyama radioheliograph visit Properties of CMEs associated with m, DH and m-to-km type II’s compared to those of all CMEs CME PropertyAllmDHmkm SEP km Speed (km/s) Width (deg) Halos (%) Acceleration(m/s 2 ) m-to-km (mkm) CMEs similar to SEP-producing CMEs km CMEs similar to metric CMEs, but acceleration is different m DH km

January Nobeyama radioheliograph visit SEP & m-to-km Events CME PropertyAllmDHmkm SEP km Speed (km/s) Width (deg) Halos (%) Acceleration(m/s 2 ) CME PropertyAllmDHmkm SEP km Speed (km/s) Width (deg) Halos (%) Acceleration(m/s 2 ) Similar number of SEP and m-to-km events  same shock accelerates electrons and protons Difference due to connectivity for particle and wider beam for bursts 33.8% of m-to-km events to the east of W10; only 13.8% of SEP events to the east of W10

January Nobeyama radioheliograph visit SEP Release height Leading edge of the CME at the time of GLE release

January Nobeyama radioheliograph visit Shocks & Type IIs Close similarity between rates of SEP events, IP type II bursts & in situ shocks Electron and proton acceleration by the same shock IP

January Nobeyama radioheliograph visit CMEs Relevant for Space Weather electron Acceleration (CME shock) proton Acceleration CME shock Plasmag Impact CME CMEs of heliospheric consequences V  1000 km/s

January Nobeyama radioheliograph visit Characteristic Speeds “1980s view” of Alfven speed Region 1: Difficult to make Type II bursts – explains Type II starting f ~150 MHz Region 2: Easy to make Type IIs below 2.5 Ro (m) Region 3: IP medium – Very Fast CMEs & accelerating CMEs produce type II Krogulec et al 1994 Mann et al Gopalswamy et al. 2001

January Nobeyama radioheliograph visit Occurrence Rates 10% of CMEs & 5% of flares have type IIs m type IIs most abundant m type IIs 2-3 times more abundant than IP type IIs

January Nobeyama radioheliograph visit Starting frequency & CME height Type II behind CME leading edge Type II & CME in different directions IP and metric drift rates can be Different if the acceleration Initially occurs in the Qperp region and later (IP) in the Q|| region (Holman & Pesses,1983)

January Nobeyama radioheliograph visit Two possible Type II Locations Flanks: Lower Alfven speeds expected. For a given CME speed, there may be a shock at the flanks, while no shock at the nose Shock may be Quasiperp at the CME flanks while quasiparallel at the nose Flank NOSE

January Nobeyama radioheliograph visit m-to-km Type II bursts and Space Weather Less than 1% of the 9000 CMEs observed during were associated with the m-to- km type II bursts. Therefore, the m-to-km bursts can isolate the small fraction of CMEs that are likely to have significant impact on the inner heliosphere It takes typically about an hour for the disturbances to reach km level Very useful for ESPs and SSCs Maybe useful for SEPs

January Nobeyama radioheliograph visit 2005 Jan 17 AR 720

January Nobeyama radioheliograph visit Interaction Event 2548 km/s 2094 km/s

January Nobeyama radioheliograph visit Summary The speed and width of CMEs progressively increase in the following order: general population, metric- associated, DH-associated m-to-km-associated m-to-km CMEs similar to SEP-producing m-to-km type IIs probe the entire Sun-Earth connected Space and the energetic CMEs propagating throughout this region. They can predict shocks of significance to Earth and other destinations in the heliosphere m type IIs alone cannot tell whether the CMEs are geoeffective. They need to have IP counterpart.

January Nobeyama radioheliograph visit Additional Comments Imaging the type IIs is ideal (SIRA) Otherwise, at least we need direction finding at sufficiently high frequencies (above 1 MHz) The lower sensitivity at higher frequencies is one thing that needs to be avoided RPW should be able to measure shock strength when the shock is still closer to the Sun